Winter has started off strong in 2019, and looks to continue! Many locales across the higher terrain have picked up close to a foot (or more) of fluffy snow over the past two days, which is great news for ski slopes. As snow continues to wind down, the big weather story going forward is a shot of Arctic air, which will pour into the North Country as we head into the weekend. Just how cold? We're talking about sub-zero lows and brutal wind chills! Let's dive into what's behind this frigid stretch. An area of low pressure responsible for the unrelenting stream of snow Wednesday & Thursday will continue to wobble over Nova Scotia before it occludes (decays) this weekend. Why is this area of low pressure important? Before it fades, the pressure gradient between the low and high pressure nosing down from the Great Lakes will allow for a persistent wind through early Saturday. Northwesterly flow on the back side of this storm will also drag down an Arctic airmass centered over Hudson Bay in Canada. We can look at the temperature forecast at the 850-millibar pressure surface (just above the summit of Mt. Mansfield) for a less noisy signal, and boy is it cold!The European model (image above) suggests values at this level will near -20°C (-4°F). This, paired with relatively clear skies and a fresh snowpack, will allow low temperatures at the surface to plummet below zero for several days. Sunday morning looks to be the coldest for most, some colder hollows will likely fall into negative double digit readings! One of our newest tools being built behind the scenes here at NBC5 is the SuperBlend, our in-house, high resolution computer guidance. This and a host of other computer models have consistently indicated that Sunday will be the coldest day this weekend.For many, the temperature alone doesn't sound terrible, especially by January standards in the North Country. However, when near-zero temperatures pair with a stiff wind near 20 mph, the result is a bitter wind chill that could fall to -20°F in some locations! I must admit, wind chills that cold are never fun.The other big question is do we see any big storms looming on the horizon? For those looking for a brief break to the snow, you're in luck. High pressure looks to dominate our weather pattern going forward, which will actually help to deflect spin in the atmosphere (vorticity) needed for storm development to our south. This means a blend of sunshine and clouds for days to come. Model guidance has also been interested in a pattern shift late next week, which could dislodge the Polar Vortex and a brutally cold airmass away from the Arctic.Will this Arctic air pour into our region? The answer is we're not entirely sure at this point.We can use ensemble computer guidance to better illustrate the likelihood/confidence in seeing this cold enter the North Country. When any particular model runs out in time, errors become more magnified past day 5 or so. This makes the overall accuracy of the forecasts in the medium range substantially lower. What's ensemble guidance, and why is it useful to meteorologists? Ensemble models slightly alter the initial conditions (snapshot of the atmosphere) fed into the computer to provide a range of possible forecasts through time. The tighter the cluster of solutions, the more confident we are of a particular outcome. The two images above show ensemble forecasts for Burlington from the European (ECMWF), American (GFS), and NBC5 (SuperBlend) models through the next 10-15 days.Notice that once we head beyond Thursday (1/17), the overall spread of the box and whiskers plots from each model get substantially larger. That signals to us that there's a lot of uncertainty surrounding how far south this second Arctic blast will reach, something we'll be keeping a close eye on here over the next couple of days!Have a question or curious about a weather phenomena? Click here to email me.

Winter has started off strong in 2019, and looks to continue! Many locales across the higher terrain have picked up close to a foot (or more) of fluffy snow over the past two days, which is great news for ski slopes.

48 Hour Snow Totals | NOHRSC

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As snow continues to wind down, the big weather story going forward is a shot of Arctic air, which will pour into the North Country as we head into the weekend.

Just how cold? We're talking about sub-zero lows and brutal wind chills! Let's dive into what's behind this frigid stretch.

An area of low pressure responsible for the unrelenting stream of snow Wednesday & Thursday will continue to wobble over Nova Scotia before it occludes (decays) this weekend.

European MSLP Forecast | Early Friday

Why is this area of low pressure important?

Before it fades, the pressure gradient between the low and high pressure nosing down from the Great Lakes will allow for a persistent wind through early Saturday.

Northwesterly flow on the back side of this storm will also drag down an Arctic airmass centered over Hudson Bay in Canada.

We can look at the temperature forecast at the 850-millibar pressure surface (just above the summit of Mt. Mansfield) for a less noisy signal, and boy is it cold!

European 850 mb Temperature Forecast | Early Saturday

The European model (image above) suggests values at this level will near -20°C (-4°F).

This, paired with relatively clear skies and a fresh snowpack, will allow low temperatures at the surface to plummet below zero for several days.

SuperBlend Low Temperatures

Sunday morning looks to be the coldest for most, some colder hollows will likely fall into negative double digit readings!

One of our newest tools being built behind the scenes here at NBC5 is the SuperBlend, our in-house, high resolution computer guidance.

This and a host of other computer models have consistently indicated that Sunday will be the coldest day this weekend.

For many, the temperature alone doesn't sound terrible, especially by January standards in the North Country.

However, when near-zero temperatures pair with a stiff wind near 20 mph, the result is a bitter wind chill that could fall to -20°F in some locations!

I must admit, wind chills that cold are never fun.

The other big question is do we see any big storms looming on the horizon? For those looking for a brief break to the snow, you're in luck.

High pressure looks to dominate our weather pattern going forward, which will actually help to deflect spin in the atmosphere (vorticity) needed for storm development to our south.

This means a blend of sunshine and clouds for days to come.

Model guidance has also been interested in a pattern shift late next week, which could dislodge the Polar Vortex and a brutally cold airmass away from the Arctic.

Will this Arctic air pour into our region? The answer is we're not entirely sure at this point.

We can use ensemble computer guidance to better illustrate the likelihood/confidence in seeing this cold enter the North Country.

When any particular model runs out in time, errors become more magnified past day 5 or so.

This makes the overall accuracy of the forecasts in the medium range substantially lower.

What's ensemble guidance, and why is it useful to meteorologists?

Ensemble models slightly alter the initial conditions (snapshot of the atmosphere) fed into the computer to provide a range of possible forecasts through time.

The tighter the cluster of solutions, the more confident we are of a particular outcome.

European & American Temperature Spread | Late Next Week

SuperBlend Temperature Spread | Late Next Week

The two images above show ensemble forecasts for Burlington from the European (ECMWF), American (GFS), and NBC5 (SuperBlend) models through the next 10-15 days.

Notice that once we head beyond Thursday (1/17), the overall spread of the box and whiskers plots from each model get substantially larger.

That signals to us that there's a lot of uncertainty surrounding how far south this second Arctic blast will reach, something we'll be keeping a close eye on here over the next couple of days!